In a field of a graphic art, a forming system for an image having a super high contrast photographic characteristic (particularly, gamma is 10 or more) is needed in order to improve reproducibility of an image with a continuous gradation by a halftone dot image and reproducibility of a line image.
There is known as a method in which a stable developing solution is used to obtain a high contrast photographic characteristic, the methods using hydrazine derivatives described in U.S. Pat. Nos. 4,224,401, 4,168,977, 4,166,742, 4,311,781, 4,272,606, 4,211,857, 4,912,016, and 4,998,604, and JP-A-3-259240 (corresponding to U.S. Pat. No. 5,221,593) (the term "JP-A" as used herein means an unexamined Japanese patent application) and JP-A-5-45761 (corresponding to U.S. Pat. No. 5,279,919). A super high contrast and high sensitive photographic characteristic can be obtained according to these methods, and furthermore, since it is allowed to add sulfite in a high concentration to a developing solution, stability of the developing solution to air oxidation is remarkably improved as compared with that of a lithographic developing solution.
However, it has found that conventional hydrazine compounds have several defects. That is, it was tried to provide the structures of the conventional hydrazine compounds with an anti-diffusible property for the purpose of decreasing an adverse influence to the other photographic materials by flowing into a development processing solution. Since these anti-diffusible hydrazine compounds are necessary to be used in a large amount for a sensitization and to increase contrast, a physical strength of a light-sensitive layer obtained is deteriorated and the hydrazine compounds are deposited in a coating solution of the light-sensitive layer. Furthermore, there has been found a problem that processing in a fatigued developing solution in which a lot of the light-sensitive materials are processed can not provide a sufficiently high contrast.
In general, a contact work light-sensitive material handled in a daylight occupies a large area as one of the light-sensitive materials for a photomechanical processing, and in this field, a high superimposed letter image quality by which even a fine Ming letter is reproduced. That has required a development of a nucleus-forming agent having a higher activity. Particularly in a daylight light-sensitive material which has such a low sensitivity as can be handled even in a daylight, since it is difficult to obtain a high contrast by the nucleus-forming agent, the nucleus-forming agent having further high activity is desired.
A silver halide photographic light-sensitive material using a hydrazine compound of the following formula is described in JP-A-3-259240: EQU R.sup.1 --S--L--C(O)--N(R.sup.2)--J--X--NHNH--C(O)--R.sup.3
wherein R.sup.1 is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heterocyclic group, and L is an alkylene group or an alkenylene group.
A silver halide photographic light-sensitive material using a hydrazine compound of the following formula is described in JP-A-2-25843 (corresponding to U.S. Pat. No. 4,912,016): EQU R--S--CH.sub.2 --CONH-phenylene-NHNH--CHO
wherein R is an alkyl group having a carbon number of 1 to 8 or a cycloalkyl group having 4 to 8 carbon atoms in a ring.
Further, a silver halide photographic light-sensitive material using a hydrazine compound of the following formula is described in JP-A-5-45761: EQU R.sup.1 --L.sup.1 --R.sup.2 --L.sup.2 --R.sup.3 --NHNH--G.sup.1 --R.sup.4
It is described in this patent that a case in which R.sup.1 is an ethylene oxide group, a pyridinium group or an alkylthio group substituted with a quaternary ammonium group is preferred. L.sup.1 represents --SO.sub.2 NR.sup.5 --, --NR.sup.5 SO.sub.2 NR.sup.5 --, --NR.sup.5 CONR.sup.5 --, or --G.sup.2 P(O)(G.sup.2 R.sup.5)--NR.sup.5 --.
However, it has been found that the defects described above can not sufficiently be improved with the hydrazine compounds concretely described in these patents.